Typically, an oil hydraulic brake is composed of a brake pedal, a distributing device, a master cylinder, a brake pipe, a wheel cylinder and a wheel brake. The wheel brake includes both disc brakes and a drum brakes. Modem vehicles use disc brakes, and in particular, disc brakes are used mostly for front wheels.
However, there is a problem in the disc brakes thus described in that discs and pads of the disc brakes tend to become wet during wet road conditions and cause slippage between the discs and the pads when a brake pedal is depressed. Thus hindering the vehicle from properly stopping.